A confirmation bias is when we look for information that supports our preexisting opinion. We start with a view of a particular issue and then search for information that upholds that view.
Although it is a bias, it is not usually intentional, meaning it’s a type of implicit bias. It is a natural tendency of the way people think to rely on shortcuts in our mental processing. It is just easier to do than subjecting our views to contradictory information, which is discomforting.
We yield to the confirmation bias when reading about politics, encountering people of particular demographic profiles, or selecting articles to read on the internet.
Definition of Confirmation Bias
Of all the heuristics and biases that psychologists have identified, none play a greater role in science than the confirmation bias. Science is supposed to be objective and without bias.
In the words of Wason (1960), one of the earliest to investigate the confirmation bias:
“…scientific inferences are based on the principle of eliminating hypotheses, while provisionally accepting only those which remain. Methodologically, such eliminative induction implies adequate controls so that both positive and negative experimental results give information about the possible determinants of a phenomenon” (p. 129).
Searching for information that disconfirms our theory is at the heart and soul of scientific research; the exact opposite of the confirmation bias.
Examples of Confirmation Bias
1. Optimistic People
Being optimistic is good for a person’s mental health, to some extent. Seeing the positive side of everything can keep us in a good mood. But optimists also seem to have a talent for ignoring negative or unpleasant information.
Being pessimistic is just the opposite. Always seeing the negative side of a situation can make us feel depressed and lose a sense of hope.
Both sides of this coin are good examples of confirmation bias. The optimist only looks for positive information and the pessimist only looks for negative information. The glass will always be half full or half empty, depending on your personal outlook.
Of course, if you are a scientist then you must be neutral and objective. Therefore, the glass is neither half full or half empty: it’s at 50% capacity.
2. Refs Making Bad Calls
We tend to think a referee made a good call when it is beneficial for our team, but if it goes against our team, there’s a good chance we will think the referee made a bad call.
Watching your favorite team lose a game because of bad officiating can be very frustrating. For some, it might seem like the end of the world. Fans on the other side of the field however, will have a completely opposite opinion.
Discussions after the game can offer plenty of examples of the confirmation bias. Fans on the losing team can rattle off a number of calls that went against their team. They can cite details of the play that support their view, and maybe even reference a few pages from the official rulebook. Fans on the opposing side can do the exact same thing in support of their team’s victory.
In most cases, as in this one, the confirmation bias applies to both sides of the same coin.
3. News Reporting
Today, many news reporters are expected to curate media that supports the political perspective of the news organization’s owners.
Reporters are supposed to be neutral and objective. At least, in theory that is how it is supposed to be. In modern times however, reality is a bit different.
In some Western countries, it is easy to see a clear and strong political bias in various news agencies. In some cases, nearly every news story will have a political tilt that favors a particular political ideology.
This is evident in the selection of stories covered, the angle presented, the facts cited, and even the types of guests interviewed.
Although the confirmation bias is usually considered unintentional, that is not always the case, especially when it comes to politics.
4. Believing a Horoscope
Horoscopes tend to be highly interpretive, allowing people to believe it no matter what: you simply find the interpretation of the horoscope that supports your own perspective.
Reading one’s horoscope can be entertaining. Who doesn’t want to know what will happen next week or discover their destiny? Maybe true love is just around the corner.
Horoscopes are deliberately written in a way that is slightly vague. If you analyze the statements carefully, you will discover that each one is open to a lot of interpretation. Events that happen afterwards could be construed in a way in which it seems very consistent with what the horoscope predicted.
True believers will always find a way to fit what happened to them with what their horoscope predicted. This is the magic of horoscopes and the power of the confirmation bias.
5. Criminal Investigations
Often, detectives will believe they know there are patterns in all their investigations. When they come up with a theory, they’ll go out there to try to confirm that theory by looking for supporting evidence.
Detectives are people too. When working a crime scene, they must look at all the evidence objectively and seek additional data to solve the crime. Maybe they have seen similar situations so many times before in their career that they develop a “working theory” about what happened.
That is where the trouble starts. Since they have a theory already, they may begin to search for evidence that is consistent with that theory. They may interview witnesses that fit a certain stereotype and ask specific questions that are also a little biased.
During the process of the investigation, the detectives accumulate more and more evidence that fits their expectations. Eventually, an arrest will occur. Hopefully, the legal system will work and the right suspect will be tried and convicted.
6. Conducting a Research Literature Review
When conducting a literature review of the available research students should read all of the studies objectively. However, they may begin their project having a preliminary theory of the phenomenon being studied which clouds their biases.
This is where the confirmation bias begins. Since they already favor a particular theory, they may input search terms that are consistent with that theory. That means the results will display studies that match the theoretical view they favor.
Instead of intentionally seeking out information that is inconsistent with their preconceived views, like a good scientist is supposed to do, they only read studies that confirm their favored theory.
During the process of writing the literature review, they describe a lot of research that supports that theory. Eventually the paper will be turned in to their research advisor. Hopefully the professor’s review will be thorough and the paper will be given back to the student to do over.
7. Stereotype Reinforcement
Stereotypes often take on a life of their own. Once formed they seem to be very hard to break. When we observe situations that involve people from specific backgrounds or demographics, everything we see will be filtered through the lens of our stereotypes.
Unfortunately, even information that is blatantly contradictory to those stereotypes can go completely unnoticed. It’s as if those actions were invisible. When this happens, it makes it impossible for the stereotype to be broken.
When recounting the situation to others, a person may only include descriptions of another person’s behavior that fit the stereotype they had for them. Thus, the stereotype is perpetuated by way of confirmation bias.
8. Forming Friendships with People that Agree with You
“Birds of a feather flock together.” This is an old saying, and it is very true. People just automatically gravitate toward others that are similar to themselves because you find them agreeable. It is human nature.
We tend to form friendships with people that are similar to us in terms of demographics such as age, race, ethnicity, and SES status. We should include socio-political attitudes in that list as well.
This creates a confirmation bias by means of self-selection. By selecting similar others, we are also by default selecting to be exposed to information and views that are consistent with our own.
Although it is comforting to have our views confirmed by others, it is also a bit unhealthy and keeps us from growing as human beings.
9. Phrasing Questions in a Survey
Survey questions can influence people into giving certain answers. If this is the case, then the study has become invalid due to confirmation bias.
Conducting a survey is a great way to gather the opinions of a large number of people in a relatively short period of time. In most situations, the goal is to obtain an objective insight into an issue or collect the opinions of others.
Phrasing the questions can be a bit tricky, however. The researchers may have already formed an opinion regarding the issue, which can lead to an unconscious bias in how they word the questions.
For example: “Why do you think the government should do more to help struggling families?” Or: “In what ways should employers give their staff more influence in marketing decisions?”
Of course, these two questions are obviously skewed in a certain direction. Each one suggests an opinion and then asks the respondent to support it. That’s not exactly the neutral phrasing that researchers are supposed to take when collecting data.
10. Placebo Effects
A placebo is an intervention – often a medication – that doesn’t actually have any benefit. For example, it might just be a sugar pill. Nevertheless, people often perceive placebos to be helpful because they’re looking for signs that confirm the placebo has worked.
Essential oils are one example. They are concentrated liquids made from various plants. The oils can be heated and evaporated using a special device or applied to the skin. Many essential oils should not be ingested orally and can be very dangerous if done so. Common essential oils include lavender, peppermint, and tea tree.
The expectation that something will work can cloud our judgement. For example, if we apply a particular oil to our skin that is supposed to make it firmer, then when we look in the mirror, we may interpret what we see as firmer skin.
The confirmation bias is at work again. In this example, it literally affects what we see.
11. Internet Algorithms
Internet algorithms help confirm our own biases because they learn about our preferences and present information to us that we’re most likely to enjoy and click on.
The use of algorithms impacts everything we do on the internet. Algorithms track the search terms we input, the ads we click on, and which news stories we select to read.
Over time, an algorithm can build a surprisingly detailed profile of our personality characteristics and socio-political views.
That profile then influences the type of information we are exposed to because the algorithms will feed us a particular type of news story or advertisement. Our profile data might be given to numerous corporations that then send us tailored content as well.
Although we may not realize it, the algorithms are creating a kind of “bubble of self-confirmation bias.” By being sent content that is already consistent with our profile, our preferences and views are being reinforced.
This is an example of a passive form of confirmation bias of which we are completely unaware.
12. Political TV Channels
In a country with a free press, it means that TV channels can be categorized based on their political leanings. For example, in the US there are 2 major networks that are obviously biased in polar opposites.
One channel, called MSNBC, is overwhelmingly liberal. The newscasters, guests, and stories have a clearly discernable agenda. The other major channel, FOX News, is skewed in the conservative direction. The newscasters, guests, and stories also have a clear political orientation.
In terms of the confirmation bias, the viewers that have a preference for one channel or the other are proactively selecting a side. By doing so, they are consciously making a choice to be exposed to information that confirms their already existing, well-ingrained perspective.
Although the confirmation bias is usually considered to be an unconscious mental shortcut, in the case of selecting a particular news channel, it seems to take on a very conscious form.
13. Biased Consumer Research
Conscious researcher bias occurs when a researcher is conducting research purely to confirm their own perspective.
Many large companies who have a vested interest in research that supports their product will pay or donate money to researchers in order to have them create research that finds the product is good.
For example, you may have heard of oil companies that supported research that denies climate change. In these situations, it is a clear example of unethical behaviors in the academic and scientific fields.
14. Judge and Jury Bias
Judges can also be highly biased in their findings. For example, in the United States, the supreme court is stacked with ‘liberal’ versus ‘conservative’ judges.
This sort of bias is rife in the legal system. Depending on the judge you get, you may get a strict or lenient perspective.
It becomes confirmation bias when a judge gives you a harsh sentence due to their stereotypical perspectives of the defendant. For example, a judge might see a single mother and think “single mothers are terribly irresponsible.” This becomes the anchor for their thought process (as shown in the anchoring bias heuristic).
Suddenly, this judge is going to want to confirm their bias against the defendant and see all evidence through that biased lens, and you may get a tougher sentence as a result.
15. Hindsight Bias
Hindsight bias is a sub-type of confirmation bias. It refers to situations when people reflect on a situation and say “well it’s obvious it would have turned out that way!” Here, we’re using the benefit of hindsight to show off our brilliance: “see, it confirmed my perspective!”.
For example, people might have seen a car crash and said “Well, it was obvious that person was going to get into a crash. They’re a terrible driver.”
However, this is hindsight bias because the situation was probably far more complex in the moment. Nevertheless, with the benefit of hindsight, we use past events to paint a black-and-white picture of something that was “obvious” and confirms how your beliefs are always correct. By doing this, we’re creating a simplified vision of the world in a way that helps to support your own biases.
16. The Halo Effect
The halo effect is a type of bias where you see someone is excellent at one thing so assume they’re excellent at everything.
For example, a company might hire a new employee who did a really great job at one project in the first week of the job. From there on, this employee becomes the ‘golden boy’ and the boss thinks he can’t do anything wrong.
The other employees may look at them and think “wow, he did one thing right, but he hasn’t outperformed since then. Why does the boss think he’s so great?”
What’s happened here is the boss has passed an initial judgement of the new employee and is now looking for examples to confirm their first impression. They’re biased toward confirming their initial belief that this is an excellent employee.
17. The Horns Effect
The horns effect is the opposite of the halo effect. It occurs when you believe someone is bad, so you see everything they do negatively.
This may happen, for example, when you’re against the politician on the other political team. Suddenly, everything he does is bad. Not because you’re objective but because you’re seeking for confirmation bias. You suddenly think small mishaps mean the person isn’t worthy of standing for office and you disagree with anything they do, no matter what.
At the same time, it’s likely that you’ll apply the halo effect to the politician you support and want to defend their every move to confirm your original perspective: that they’re the best politician!
Confirmation bias is a very self-serving type of bias. It can take many shapes and effect our thinking processes across a wide range of contexts. Sometimes it clouds our perceptions of not-so-significant events such as the outcome of a game or the effectiveness of essential oils.
On the other hand, it can also have a tremendous impact on quite significant events. For example, how detectives approach solving a homicide or the political leanings of where we get our news. Even the algorithms that are such an integral part of the internet are feeding us information that confirms our already existing opinions and preferences.
The confirmation bias generates a vicious cycle that perpetuates our views on the world around us and leads to the formation of a thick-layered bubble from which we live.
How to burst that bubble is a question we all must consider if we hope to grow as individuals.
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